9306369 Vander Wall This project examines the interactions between plants, animals, and the physical environment by fluctuations in seed water content and how they influence rodent foraging success. Most seeds are hygroscopic, readily imbibing water whenever the soil becomes moistened. If conditions are unsuitable for germination, the seeds gradually lose moisture as the soil dries out. Consequently, seeds vary in water content over time as the weather changes. Rodents readily find moistened seeds using their olfactory sense but often appear to have difficulty finding seeds when the seed s and the substrate are dry. Despite the well known characteristics of hygroscopic seeds and the demonstrated inability of some rodents to find dry seeds, the detail of how deed/soil moisture influences an animal's ability to find seeds appears to be almost totally unknown. Field & laboratory work focuses on the foraging success of three species of rodents searching for two types of seeds at various controlled or monitored moisture levels. The response curves of rodent foraging success at various levels of seed water content will be determined under controlled conditions. The water content of seeds and soil will be monitored in the field over several weeks and related to rodent foraging success. %%% Plant animal interactions play important roles in population & community ecology, but the role if the physical environment in mediating these int eractions has received little attention. By focusing on caching behavior of rodents, this project contributes to understanding dynamic's of soil seed banks, plant populations & rodent foraging. ***
